1 / 24

W I F I

W I F I. Frekvencie 802.11. 2.4 GHz 13 kanálov - Eur ópa ; (11 kanálov – USA) < 2 . 412 2 . 472 > [ G Hz]. Modul ácia. FHSS - Frequency Hopping Spread Spectrum 802.11 (1997 - BreezNet, max. 2 mbps) EEE 802.15.1 - Technologie Bluetooth

adeola
Download Presentation

W I F I

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. WIFI

  2. Frekvencie 802.11 • 2.4 GHz 13 kanálov - Európa; (11 kanálov – USA) < 2.4122.472 > [GHz]

  3. Modulácia • FHSS - Frequency Hopping Spread Spectrum802.11 (1997 - BreezNet, max. 2 mbps) EEE 802.15.1 - Technologie Bluetooth • DSSS - Direct Sequence Spread Spectrum802.11 (1997 - 2 mbps, 1999 - HR/DSSS, 11 mbps) • IR - Infra Red • OFDM - Orthogonal Frequency Division Multiplexing802.11a (1999) a 802.11g (2003) • PBCC - Packet Binary Convolution Coding802.11b+ (2002)

  4. topológie: IBSS; BSS; ESS Ad-hoc (resp. IBSS „Independent Service Basic Set“)

  5. Infrastructure hoc (resp. BSS „Basic Service Set“)

  6. ESS „Extended Service Set“

  7. Rozdelenie a administrácia staníc

  8. Max.100 [mW]

  9. Zisk (Útlm)[dB] [dBm] [W]

  10. Koaxiálne káble

  11. Prostredie(vzduch)

  12. Všesmerové antény Vyžarovací diagram z boku Vyžarovací diagram zhora

  13. Sektorové antény Vyžarovací diagram z boku Vyžarovací diagram zhora

  14. Smerové antény Vyžarovací diagram z boku Vyžarovací diagram zhora

  15. Polarizácia • Lineárna • kruhová horizontálna vertikálna pravotočivá ľavotočivá

  16. Konektory

  17. dvojcestné útlumové členy

  18. Bleskoistky

  19. 2 x DWL-900AP+ v režime bridge; 1,5 km Typické údaje o citlivosti DWL-900AP+ -85 dBm (11 Mbit/s) -88 dBm (5,5 Mbit/s) -89 dBm (2 Mbit/s) -92 dBm (1 Mbit/s)

  20. Koordinácia prístupu k médiu Použité správy protokolu CSMA/CA: (Carrier Sense Multiple Access /with Collision Avoidance) RTS – Request to Send CTS – Clear to Send ACK – Acknowledge [NAV (Network Allocation Vector)]

  21. Bezpečnosť • MAC filtrácia • WEP(64; 128) (Wired Equivalent Privacy) rotácia kľúčov • WPA (WiFi Protected Access)

  22. Šifrovací algoritmus RC4(prúdová symetrická šifra) KSA – Key Scheduling Algorithm PRGA – Pseudo Rangom Generator Algorithm XOR – eXclusive OR

  23. WEP proces

More Related